I think this is more common than most people think. I'm not sure why he's doing this. Boredom perhaps? I think you should have another talk with him and find out why he likes doing this. Ask him to be honest and upfront. Tell him again how this behavior makes you feel. While I don't really consider this cheating the act of him doing that is hurtful and is having a negative effect on your relationship.
If it is out of boredom, maybe getting out and doing things with friends instead of interacting on the computer would be better for him. Or investing in a new hobby he can be proud of.
If it is because he is feeling that the spark between you and him has dimmed and he uses that as a way to connect to others then maybe re-evaluating the relationship and figuring out what you can do to bring the spark and chemistry back. I have been with the same guy for almost 6 years and I know that at times things can get very routine. So you have to work to keep from getting in a relationship rut. Usually people go outside the relationship because they aren't getting something that they need. Ask him to express what it is he needs. More intimate time? Maybe he wants you to fullfil more of his desires. Maybe he thinks your sex life has gotten a bit routine and boring. All of these things are fixable if you are both willing to fix them.
If he is willing to stop this behavior for you then maybe you can do something for him in return. Hope it works out for you, relationships are always a work in progress.
This answer was edited by Skoolie 338 days ago.
Reason: spelling
